利用光子晶体调控表面等离极化激元

Surface-Plasmon-Polariton Manipulation Using Photonic Crystals

研究了空气/金属-介质超晶格结构界面处的表面等离极化激元。采用传输矩阵法,得到了金属-介质层状超晶格结构的能带分布以及表面等离极化激元色散曲线,发现通过调节界面处金属层厚度可以有效地调控表面电磁模式分布。若在金属层中外加静磁场,破坏了系统的时间反演对称性,表面等离极化激元表现出非倒易的特性。尤其在一定频率区间,会出现单方向传播的表面等离极化激元。

The existence of surface plasmon polaritons （SPPs） at the interface between air/metal-dielectric layered systems is demonstrated. Using the transfer matrix method, we calculate the band structure of periodic metal- dielectric layered system and the dispersion relation of SPPs. It is found that we can effectively tune surface modes by varying the thickness of the top metal layer. Moreover, in the presence of static magnetic field, the time reversal symmetry of systems is broken, and nonreciprocal SPPs can be gotten. In particular, such a system can provide a frequency range where one-way SPPs are allowed.